#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e5;
typedef long long LL;
const double pi=3.1415926;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
int main(void)
{
  cin.tie(0);std::ios::sync_with_stdio(false);

  double d,h,v,e;cin>>d>>h>>v>>e;
  d/=2;
  if(e>=(v/(pi*d*d))) cout<<"NO"<<"\n";
  else{
    printf("YES\n");
    printf("%.10f\n",h/(v/(pi*d*d)-e));
  }

return 0;
}
